Brake mechanism



S. SCHNELL Aug. 9, 1932.

BRAKE MECHANISM Filed Oct. 2, 1950 Fig.3

Inventor v STEVE SCHNELL BY Atty.

Patented Aug. 9, 1932 UNITED STATES PATENT OFFICE STEVE SGH'NELL, OF ST LOUIS, MISSOURI, ASSIGNOR TO WAGNER ELECTRIC CORPO- BATION, OF ST. LOUIS, MISSOURI, A CORPORATION OF DELAWARE BRAKE mncnmsu Application filed October .2, 1930. Serial No. 485,889.

M invention relates to brake mechanism, its 0 j ect being to produce an improvement in brake shoe guiding and adjustment means.

In the accompanying drawing Figure 1 is a side elevational view of a braking apparatus embodying my invention (the brake drum being omitted) Figure 2 is a vertical cross sectional view on the line 22 of Figure 1, the brake drum being also shown; Figure 3 is a cross sectional view along the line 33' of Figure 1, showin one of my improved brake shoe guides; figure 4 is a cross sectional view along the line 44: of Figure 1, illustrating my improved shoe clearance adjusting means; and Figures 5 and 6 are plan views of the cam and washer elements, respectively, of the said last mentioned adjusting means.

In the drawing 1 represents the usual supporting or backing plate on which the brake shoes 2 are pivotally supported at one end as indicated. The shoes may be actuated by suitable means, such as of the hydraulic type illustrated, and are biased to ofi position in the usual manner by spring 3, there off position clearance fromthe drum 4 being determined by the adjustable stops 5. As shown, the shoes are of T-section and since their pivots pass directly through their webs, the pivot bearing surface formed is too narrow to, prevent lateral rocking of the shoes and my invention in one aspect relates to improved shoe guides 6, the construction of which is best illustrated in Figure 3. These guides are angle pieces of malleable metal, one web being secured to the backing plate and the other being provided with an open ended slot which receives the web of the shoe, permitting the free operative movement of the shoe but preventing mot-ion in either direction transverse to the plane of operative movement.

The inner walls of the slots preferably have protuberances to engage the sides .of the shoe webs with substantially point contact, as indicated in Figure 3, which not only reduces friction between the shoes and the guide but facilitates the adjustment of clearance between these parts in the manner to be now described.-

For cost reasons considerable manufacturing tolerance must be allowed in the thickness of the webs of a shoe-particularly when the shoes are formed of rolled T-section, and then bent into arcuate shape-since not only will there be variation in the web thickness of the T-bar, but also the change in thickness of the web during the operation of rolling the bar into arcuate shape will not be uniform in all portions of the web. In accordance with my invention, therefore, I form the shoe guides with over size openings at the shoe engaging points and after the shoes are assembled on the backing plate I strike the outer edges of the guides with a hammer to bend them inwardly as far as the shoe web. will permit, having found that this method enables me to quickly produce a close and uniform clearance between the guides and the webs in that the inner portions or fingers of the guides, although driven against the shoe web while the latter abuts the opposite side of the guide, will always spring back slightly and to a sufiicient extent to avoid any binding.

As shown in Figure 1, two guides are preferably provided for each shoe, one near the free end and the other intermediate this point and the shoe pivot.

t necessary to make clear the advantage of the means described for the making of the proper operative assembly of brake shoes in relation to their supports.

In Figure 4 I have illustrated an improved means for adjusting the ofi position clearance of the brake shoes, these means being generally designated by the numeral 5 in Figure 1. They comprise a cup-shaped cam 7 non-rotatively and eccentrically mounted on the end of headed bolt 8, which bolt passes through, and has bearing in, the backing plate and is surrounded by compression spring 9 interposed between the outer surface of. the plate and the head of the bolt. The bolt also non-rotatively carries friction disk 10 on which the eccentric 7 bears and which. in turn engages the inner face of the backing plate. The disk is slightly cupped,

as shown, whereby good frictional contact 00 is believed that no further discussion is with the plate at points spaced by the bolt is secured. Since the bolt is longitudinally movable in its bearing in the backing plate the spring 9 maintains frictional pressure 5 between the washer and the backing plate, whereby the eccentric 7 is maintained in the rotative position to which it is adjusted by rotation of the bolt 8, and thus forms an adjustable stop determining the oil' posi- 10 tion clearance of the shoes and the drum. The adjustin means just described has the advantages 0 simplicit of construction and operation, and that t e spring is visible whereby it can readily be determined whether it is in condition to operate properly.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In brake mechanism, the combination with a brake shoe, of a flat malleable guide member positioned at right angles to the plane of the shoe having a slot to receive an element of the shoe to retain the shoe against lateral movement in either direction, said as guide member being deformable by hammer blow to adjust the clearance between it and the shoe.

2. In brake mechanism embodying a support, a shoe mounted thereon and means car- 30 ried thereby forming spaced shoe guide elements one of which is deformable, the method of manufacture which comprises initiaL ly locating the guide elements at excess distance from each other, mountin the shoe on the support and with a part etween the guide elements, and then forcing the deformable element toward the other to reduce the space between the elements to the thickness of the included part of the shoe plus a suitable clearance.

3. In braking mechanism embodying a brake shoe and a fiat malleable guide member having its width ositioned at right angles to the plane of the brake shoe and means forming a shoe abutment aligned with but spaced from the guide member, the method of manufacture which comprises positioning an element of the shoe between the guide member and said abutment, and then deforming th guide member by hammer blows on one of its edges applied toward said abutment.

In testimony whereof, I hereunto afiix m signature, this 26th day of September, 19

STEVE SCHNELL. 

